Human power
Human power is timed rate of work done by a human. Most humans can exert only less than one-half horsepower for a duration of a few minutes. World records of power performance by humans are of interest to work planners and work-process engineers. The average level of human power that can be maintained over a certain duration of time, say over the extent of one minute or one hour is interesting to engineers designing work operations in industry. Flight across the English Channel by a pilot using only his human power (and incidental lifts from some rising air currents usually offset by low-level downdrafts) exhibits one stark use of human power. Measuring Human Power There are many ways scientists and engineers measure human power. The huge industry of body-weight control relates to human power as calories are counted for a day's time, while the International System of Units has the watt (W) as the unit of measure for power. Conversion factors to reach expressions in other units can be handy, e.g., if one wants to convert ft-lbs/s to watts (W), or watts to horsepower (hp), then that can be done to fit particular discussions. E.g., 1 hp = 745.69987 W. Defining the action would be part of a story about a particular work effort that gives a power rating. Human Power for Powering Vehicles The rickshaw is just one form of a HPV. There are HP-bicycles, HP-streamlined bicycles, HP-car, etc. The vehicles sometimes have more than one human powering the vehicle--a team effort occurs. Ancient mariners had large teams of slaves powering the rowing of large boats. Row boats are driven by HP. External links for this section: * International Human Powered Vehicle Association * Unusual Human Powered Vehicles Human Power for Powering Machines (HPM) Muscles are just one part of the human that provides energy to do the work to form power. The heat of human bodies has also been used to do work, like warming offices, bed chambers, food, another human, etc. Blowing up a toy balloon or a latex glove in preparing to place the glove over one's hand uses human power to effect changes. Physically challenged people might be limited to using their head and neck to do work in a certain amount of time. To move eye lashes accomplishes work in a certain amount of time, slowly or quickly. Machines driven by movements of the foot have received attention from ancient times. External links for this section: * W.F. & John Barnes Patented Foot-Powered Machinery * HP for Generating Electricity for Real Time Use or for Storage Human power has been used to generate electricity that is then used directly or stored for future use in various storage devices. Electrical generator External links for this section: * Shaking Up Some Energy Human Power for Powering Aircraft (HPA) Some HPA have the pilot hung tensionally below the lifting wing (thus they are human-powered aircraft of the hang glider type), but not all where the pilot may be in the wing or above the wing. Human power that is strictly only a part of the power source of an aircraft is still important; the human power used to extend a short glide to a longer glide is a human-powered aircraft. External links for this section: *[http://www.skytec-engineering.de/hpa.htm Vélair 89] *Man Powered Aircraft Group of the Royal Aeronautical Society *Human Powered Aircraft Group (HPAG) at Virginia Tech *HPA at Nihon University *[http://www.flycycleart.webcentre.ca/ Flycycle: Human Powered Flying-wing] Human Power in Athletics What level of power was exerted by the human who broke the world record in the running high jump, running long jump, weightlifting's snatch action, etc. ? For the HP-aircraft to become a popular sport, engineers are aiming to design aircraft that will be affordable and successfully flown with the power output that a human sportsperson can exert. A certain amount of HP is used to effect a winning effort in the athletics event shot put, high jump, or hammer throw. External links for this section: * Shot put of 12 lbs pushed to a certain altitude during a work effort lasting 0.63 seconds is an example of human power in athletics. Human Power and Green Revolution References U.S. Patents * IMPROVEMENT IN DRAG-SAWS: US Pat. 224987 http://www.google.com/patents?id=DDRjAAAAEBAJ& * VELOCIPEDE: US Pat. 233396 http://www.google.com/patents?id=EZtwAAAAEBAJ Category:Human power